Mechanism for swinging and lifting doors and the like



A. LODGE Oct. 17, 1967 3,346,992 MECHANISM FOR SWINGING AND LIFTINGDOORS AND THE LIKE Filed Aug. 26, 1965 2 Sheets-Sheet l ilbmmhrr Oct.17, 1967 LODGE MECHANISM FOR SWINGING AND LIFTING DOORS AND THE LIKE 2Sheets-Sheet 2 INVENTOR.

Filed Aug. 26, 1965 Patented Oct. 17, 1967 3,346,992 MECHANISM FDRSWINGING AND LE TING DOORS AND THE LIKE Alvin Lodge, Erie, Pa, assignorto American Sterilizer Company, Erie, Pin, a corporation of PennsylvaniaFiled Aug. 26, 1965, Ser. No. 482,765 13 Claims. (Cl. 49-255) ABSTRACTOF THE DISCLOSURE The mechanism disclosed is made up primarily of ascrew and nut arrangement, one of which is attached to a door and theother to a motor. The motor arrangement mounted on the sterilizer drivesthe screw so that it swings the door until the door strikes anobstruction. Then, the screw raises the door by a jamming action on thethreads of the nut.

The lifting mechanism is so designed that when the motor starts torotate a gear to which the nut is attached, the door will swing openuntil it strikes the edges of the pit or until a follower strikes theedge of a cam slot. Then the nut mechanism will move up the incline ofthe threads and thus will lift the door until the door clears the top ofthe pit or until the follower clears the top of the slot and furtherrotation of the motor swings the door to full open position.

This invention relates to mechanisms and, more particularly, tomechanisms suitable for lifting and swinging a door, for example, asterilizer door.

It is, accordingly, an object of the present invention to provide animproved door opening mechanism.

Another object of the invention is to provide a door opening mechanismwhich is simple in construction, economical to manufacture, and simpleand efiicient to use. Still another object of the invention is toprovide an improved mechanism for accomplishing a novel combination ofrotary and axial motions.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawing and more particularlypointed out in the appended claims, it being understood that changes maybe made in the form, size, proportions, and minor details ofconstruction without departing from the spirit or sacrificing any of theadvantages of the invention.

In the drawings:

FIG. 1 is a partial isometric view of a door and operat ing mechanismaccording to the invention shown supported in a pit;

FIG. 2 is a partial front view of the mechanism shown in FIG. 1 with thedoor in closed position and the locking mechanism actuated;

FIG. 3 is a view similar to FIG. 2 showing the locking mechanismreleased;

FIG. 4 is a top view of the lifting mechanism showing the door in threeseparate positions in phantom lines;

FIG. 5 is a partial cross sectional view taken on line 55 of FIG. 2;

FIG. 6 is a view partly in cross section taken on line 6--6 of FIG. 5;and

FIG. 7 is an enlarged view of the cam and follower arrangement taken online 77 of FIG. 6.

Now with more particular reference to the drawings, a door 10 is shownwith a power lift assembly 11 supporting it on a sterilizer 30 or thelike. A hinge assembly 12 supports the door for swinging on thesterilizer 3'0 which may be a sterilizer of an ordinary steam chamberdesign. The sterilizer has the cars 31 fixed to it and they receive ahinge pin 17. The hinge pin 17 is also received in brackets 33 which arefixed to the hinge 34. Thus, pin 17 can slide up and down in the ears 31when the door 10 is lifted and the door 10 can also swing around the pin17.

The door 10 has rollers 35 fixed at its lower edge which will engage theedge of a pit 36 when the door is in lowered position and may engage theside walls of the pit when the door is swung upwardly. The door has alocking mechanism 26 having arms 25 which may be operated to lock thedoor in closed position. This locking arrangement is conventional andmay be generally of the type disclosed in patent application, Ser. No.2,592,705.

The door lifting and operating mechanism is more specifically shown inFIGS. 5, 6, and 7. These figures show the lifting assembly 11 attachedto the door 10. A screw shaft 14 has a spiral thread 21 thereon which isin the form of a spiral groove that has a pitch angle that will allow itto operate in the manner desired. A pitch angle of thirty degrees hasbeen found to be satisfactory. The screw 14 is fixed to the bracket 24and bracket 24 is in turn fixed to the door. The bracket 24 has adownwardly extending leg indicated in which the follower stud 28 isreceived. Follower stud 28 has a roller 29 on it which is received inthe cam slot 40 in the plate 41. The plate 41 is fixed to the frame ofthe sterilizer.

It will be noted that slot 49 has a generally horizontal portion 42 anda vertical portion 43 so that the roller 29 will first move horizontallyand then upwardly to follow the slot and then move along the top edge 44of the plate 41. Since door 10 is fixed to bracket 24, the door 10 willfirst swing, then raise, then swing again.

The gear 18 is received between the brake linings 19 which are, in turn,fixed to the brake shoe arrangement 46 to provide a safety slip clutcharrangement to protect the mechanism in case of overload. The brakeshoes are themselves rotatably received between anti-friction bearings20 and they freely rotate therein. These brake shoes are keyed to thelifting nut 22. The motor 23 drives the shaft 48 and, from it, the gear49 and thence through the shaft 50 to the worm gear 51 which, in turn,drives the gear 18.

In operation, when the door is in the closed position, the motor 23 willbe started. This will drive gear 18 and will rotate the nut 22 with thescrew 14 and will swing the door out until the roller 29 strikes theedge of the vertical part 43 of the slot or until the wheel 35 strikesthe edge of the pit. The nut will then jam against the spiral threads onthe shaft 14 and will force the nut 22 to move up along the threadsuntil the roller 29 rides above the surface 44. Then the nut will againturn with the screw and swing the door to open position.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood i broadly novel as is commensurate with the appendedclaims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A mechanism for rotating a work member and for swinging said memberin a predetermined sequence comprising a rotatable screw member,

a spiral groove in the outer periphery of said screw member,

a nut member,

means to rotate said nut member,

thread means conecting said nut member to said screw member,

a fixed member,

cam means on said fixed member,

cam means on said screw in operative engagement with said cam means onsaid fixed member for guiding said screw in a predetermined sequence ofaxial and rotary motion,

and means on said screw for connecting said Work member thereto.

2. The mechanism recited in claim 1 wherein said thread means comprisesa spiral groove in said nut member,

balls in said grooves,

each said ball being disposed half in one said groove and half in theother said groove.

3. In combination, a door and opening means on said door,

tached to said chamber, and an opening mechanism for said door,

said door being attached to said chamberby means of a verticallyextending hinge pin,

hinge members slidably supported on said pin,

said door being fixed to said hinge members,

and means connected between said door and said chamber to swing saiddoor toward open position until it engages an obstruction, then to liftsaid door until said door clears said obstruction, then to swing saiddoor to full open position.

5. The combination recited in claim 4 wherein said means to swing saiddoor and to lift said door comprises a motor,

a nut connected to said motor,

a screw threadably received in said nut,

means on said screw to connect to a member to be moved in apredetermined path,

and guide means for guiding said member in said predetermined path assaid screw is forced to rotate and move axially by said nut, driven bysaid motor.

6. In combination, a sterilizer chamber, a door swingably supported onsaid chamber, and opening means to swing said door partly open, thenmove saiddoor upwardly, and then swing said door fully open,

said opening means comprising a screw,

nut means on said screw,

means to drive said nut,

means attaching said door to said screw,

fixed cam means having a contour,

and follower means on said screw engaging said cam means,

said screw rotating and moving axially when driven by said nut wherebysaid door is moved upwardly and swung in accordance with said contour ofsaid said door being attached to said screw,

said nut means being adapted to move said screw axially so that saiddoor will move up to clear obstructions,

swing means on said door, said nut being further connected to said swingmeans on said door to swing over said obstructions.

8. In combination, a chamber, a door on said chamber, and opening meanson said door to swing said door into engagement with an obstruction,then lift said door over said obstruction, and then swing said doorfully open,

said opening means comprisingv a screw connected to said door and drivennut means on said screw,

said screw having means to move axially when said door is held againstswinging and being adapted to swing said door when said door is free toswing.

9. In combination, a sterilizer chamber mounted in a shallow pit, a doorswingably supported on said cham: her with the lower edge of said doorbelow the top surface of said pit, and opening means for said door,

said opening means comprising a vertically extending screw attached tosaid door,

and a driven nut on said screw,

said nut connected-to said screw to move said screw axially to lift saiddoor over said top surface of said pit when said door engages said pit,

said nut being adapted to swing said door therewith when said door ismoved above said pit top surface.

10. The combination recited in claim 9 wherein said door has rollermeans on its lower edge adapted to engage the inside surface of said pitwhereby said.

said follower means slidably engaging said slot whereby 1 said swingingmember is urged to swing when said follower means moves in one said partof said slot,

said swinging member being urged to be lifted when said follower meansmoves in another part of said slot.

12. The mechanism recited in claim 11 wherein said means for supportingsaid member comprises a bracket having a part attached to said shaft anda part extending generally parallel there-to,

said follower being attached to said part of said bracket that extendsparallel to said shaft.

13. The mechanism recited in claim 11 wherein said nut has a gearattachedzthereto and motor means is connected to said gear to rotate it.

References Cited UNITED STATES PATENTS 2/1943 Simpson 7489.15 4/ 1963Linderfelt 49-317 X FOREIGN PATENTS 23,564 10/1902 Great Britain.

DAVID J. WILLIAMOWSKY, Primary Examiner.

J. K. BELL, Assistant Examiner.

3. IN COMBINATION, A DOOR AND OPENING MEANS ON SAID DOOR, SAID DOORBEING ADAPTED TO BE SUPPORTED IN A PIT, SAID PIT BEING DEFINED BY A SIDETERMINATING IN A TOP EDGE DISPOSED AT A HIGHER LEVEL THAN THE EDGE OFSAID DOOR, SAID OPENING MEANS HAVING MEANS THEREON TO SWING SAID DOORINTO ENGAGEMENT WITH SAID SIDE OF SAID PIT, SAID OPENING MEANS HAVINGFURTHER MEANS TO LIFT SAID DOOR ABOVE SAID TOP EDGE OF SAID PIT AND TOTHEN SWING SAID DOOR TO FULL OPEN POSITION.